Definition of immunoglobulin A receptors on eosinophils and their enhanced expression in allergic individuals

J Clin Invest. 1993 Oct;92(4):1681-5. doi: 10.1172/JCI116754.


Fc alpha receptors (Fc alpha R), detected by the binding of IgA and by anti-Fc alpha R antibodies, were found to be differentially expressed on eosinophils and neutrophils. Neutrophils were the major granulocyte population expressing Fc alpha R, and they expressed much higher levels of Fc alpha R than eosinophils. The expression of Fc alpha R by eosinophils could be upregulated approximately threefold by Ca2+ ionophore treatment in a dose- and time-dependent manner. This effect, which was blocked by a chelating agent, was not duplicated by other cellular stimuli. Eosinophils in allergic individuals displayed enhanced Fc alpha R expression, whereas neutrophils did not. The Fc alpha R on eosinophils had a higher molecular mass (70-100 kD) than those identified on neutrophils (55-75 kD). However, removal of N-linked carbohydrates from Fc alpha R of eosinophils and neutrophils revealed a major protein core of 32 kD for both cell types. The data indicate that expression of Fc alpha R molecules with a characteristic glycosylation pattern is upregulated on eosinophils in allergic individuals.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Antibodies, Monoclonal
  • Asthma / blood
  • Asthma / immunology*
  • Calcium / pharmacology
  • Egtazic Acid / pharmacology
  • Electrophoresis, Polyacrylamide Gel
  • Eosinophils / drug effects
  • Eosinophils / immunology
  • Eosinophils / metabolism*
  • Female
  • Humans
  • Immunoglobulin A / blood
  • Kinetics
  • Male
  • Molecular Weight
  • Receptors, Fc / biosynthesis
  • Receptors, Fc / isolation & purification
  • Receptors, Fc / metabolism*
  • Reference Values
  • Rhinitis / blood
  • Rhinitis / immunology*
  • Up-Regulation / drug effects


  • Antibodies, Monoclonal
  • IgA receptor
  • Immunoglobulin A
  • Receptors, Fc
  • Egtazic Acid
  • Calcium